Tom M'Guinn

3 liter motors need not be any more exotic nor have any more expensive custom parts than a 2.5. The only part that must be "custom" are the pistons, but the Malhe/Andial pistons are as close to stock as anything people are using in 2.5's these days. I'd agree a bone stock motor will last longer than a highly modified motor, but there is nothing inherently less reliable about a 3 liter vs. a 2.5. Both can be built well, and both can be built to self-destruct on initial start up.

gt37vgt

i think 2.5's do see more un broken fast driving miles than 3.0's generally speaking but uselly at fualt of the driver or tuner not engine

Darwantae951

Probably because there are more properly built 2.5s than 3.0s. Not many people have taken the time and money to properly build a 3L.

gt37vgt

what are you talking about "properly" ???

DivineE

I have a big stake in the 3.0+ club and I love the way they drive. Anyone who's ever tried to follow a 3.0 car in a 2.5 both sticking to 4500rpm will know just how big the difference is! It's incredible. Following Paul home on his 3.2 running an open wastegate when he first picked it up. I was trying to follow in a standard 250 turbo and sticking to the same 4500rpm limit. I ended up driving full throttle changing at 5000rpm up the slip road onto the duel carrigeway and Pauls car just drifted away from me effortlessly like a ghost. When I spoke to Paul about it he didn't even realise I was trying to keep up. It wasn't untill I first drove my own 3.2 that I realised just how effortlessly it gains speed. You barely have to do more than lift the clutch to keep up with normal traffic.

..But what would you build if you wanted 350hp and would you recommend a 3.0 using the original S2 / 968 block and just pistons for 2 years of 10 hour races?

gt37vgt

yeh there is a guy near me who ran one at 13psi in a power to weight limited Porsche challenge series as far as i know it raced fine for a few years ..
but M14 head studs and god knows what it was no cheapie ...

333pg333

It probably doesn't have to be that difficult or expensive. As Tom says, it's mostly just the pistons and you'd do Rods but you don't actually have to. As Adam says though, the tune has to be handled properly or buy something like a VR kit and be close to the mark. For a decent amount of torque grunt without going crazy in the hp stakes, you could do something pretty simple. As Ben suggests, there really is a quantifiable difference with that extra capacity. With the odd outing in big bore cars I can agree with that. You can drive them on torque much more than revs alone.
Once you want to up the stakes to 500-600-700hp then sure, the ingredients need to differ...but only fools shoot for this kind of power...

Duke

As the song goes, "only foooools ruuuuush iiiiiin"

gt37vgt

I touching moment of self awareness you guys .
yep its defiantly the absolute power that absolutely corrupts

blade7

Over the last year or so I've had the chance to buy three 2.7 engines, and I've thought a 3.0 block could be built for around £3.5k ($5k) barring unforseen expense, that's pistons, rods, crank and liners etc, but just about everyone that's done the conversion seems to cost it at least 3 times that price with all the add ons, for the time being it seems crazy to pull my fit 2.5 engine and blow many $000's that I'd never see again if I decided to sell the car sometime in the future.

gt37vgt

Blade i bet thats not a intended 350 hp 3lt ..
putting a crank and a set of pistons in a 2.7 to make it a 3.0 turbo i cant see how it spirals out of control..with the cost of the 2.7 yeah it will be more than 5k but not 3 times ...
i honestly believe i will convert my car to 3.0 for less than 3k and in the grand sceame of things thats realy not that bad considering we have all spent double that on bolt ons

blade7

Stop that right now or I will be looking for another 2.7 , the 2.7 engines were around £300 so peanuts really, I'd think a basic 3.0 build would still need a stronger clutch, bigger turbo and better engine management, aren't the rods and pistons £1k per set, then there's the block prep unless you are lucky and use standard bores, I think the big bills came with all the toys but the guys that have already done it are the ones that know the end cost.

Darwantae951

It all depends on what you want and are willing to buy. When you're done, please let me know how much it cost you for everything. The engine itself isn't what makes the total cost so much.

gt37vgt

bigger bigger bigger more more is
ok we all know the more we climb the steeper it gets so every hp is more expensive than the last ..
I for my 3k I'm only talking about what's below the head gasket .all my stuff is second hand execpt rings and bearings I've done heaps of my own work like knife edging the crank making my own oil squirter's probably crank scraper baffles and yeh there is easy another 5000 tied up in there but i realy think that could be 3000 if i was only shooting for 400hp.

I believe no matter what engine no matter what the cost rods pistons no matter how strong the standard rods are etc as soon as you decide to undo a con rod bolt some strange chemical is released and you just loose the plot
bottom ends are not expensive they just make us crazy .

DivineE

Besides the exhaust valves and springs in the 2.7 head. There are also a few pipes that come out in the wrong places that need to be adapted and you cant ignor the costs of the obvious bits that you just can't bring yourself to not do when you strip an engine. Studs, oil and water pump, seals, head gasket, bottom gasket, shells for the crank, they never get mentioned but it all adds up. Plus your bound to create breakages in a few age old wires so nothing will work and you'll spend hours chasing electrical gremlins, replacing wires etc to get it working again..

No one seems to feel the need to do any of this when they fit a new turbo and maf to their 2.5 to get 350hp and they never seem to have problems.

I know this is kind of irrelivent to the original poster but for others considering similar it's worth noting that a diy 3.0 conversion is not the cheap option.